The invention relates to systems and methods for filling and pressurizing a container for dispensing a product, and to the corresponding containers, and more particularly to containers that can be pressurized, such as by a consumer.
Many household products are dispensed from pressurized containers through a dispensing valve, which containers are generally referred to as “aerosol containers.” Conventional aerosol containers are usually pressurized by a volatile liquid propellant, which provides an adequate pressure for dispensing even after a portion of the product has been dispensed from the container.
When filling conventional aerosol products, a manufacturer fills a can with the product and promptly charges it with the volatile propellant. The filled can, in a ready-to-use form, is then shipped according to U.S. Department of Transportation rules. For example, container designs given a DOT-2Q designation must be rated to withstand 270 psi and container designs given a DOT-2P designation must be rated to withstand 240 psi.
Conventional aerosol containers may be configured such that, for example, the product and propellant are in contact, or the product is housed in a bag within the can while the propellant is housed outside the bag, or a piston separates the product from the propellant. An example of the latter is EarthSafe Dispensing Technology, marketed by Crown Cork and Seal.
Aerosol cans are moving towards non-hydrocarbon propellants using compressed gas for many reasons, such as regulatory hurdles, consumer pressure for environmental reasons, etc. But compressed gas aerosols suffer from several disadvantages, including:                Internal can pressure decreases over time as the compressed air is depleted with use.        A significant volume of the container is required for the non-hydrocarbon propellant (roughly 40% in typical aerosol applications).        Unlike hydrocarbons which re-pressurize the container each time, the spray and/or delivery performance of compressed gas propellant based aerosols changes over time.        